Base fuse



May 22, 1923.

1.4. WOODBERRY BASE FUSE Fiiedsept. 20. 1919 2 She eps-Sheet 1 May 22,1923.

- 1,456,204 J. H. WOODBERRY BASE. FUSE Filed Sept. 20, 1919 2Sheets-Sheet 2 Patented May 22, 1923.

J'QHN WOODBERRY, THE UNITED STATES ARMY.

BASE FUSE.

Application filed September 20, 1919. Serial ,No.,325,277.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L., 6 25.)

To all 107mm 2'25 may concern:

Be it known that I, J OHN H. lVooDBERRY, lieutenant colonel, UnitedStates Army, a citizen of the United ,States, stationed at Vashington,District ofColumbia, have invented an Improvement in Base Fuses, ofwhich the following is a specification.

The invention described herein maybe used by the Government, or anyofits officers or employees in prosecution of work for the Government, orby any otherperson in the United States, without payment of any royaltythereon. i

The object of my invention is, in general, to provide an improved base.detonating fuse, of the selective mechanical delay type, i. e., a fusethe action of which affords, through mechanical means, an automaticselective delay in firing, the delay, in all cases, being proportionalto the duration of the .resistance to penetration encountered by theprojectile, .upon impact.

-More specifically, the object is to provide a fuse, having a normallyrestrained and unarmed firing pin, embodying novel means for arming thefiring pin. i

Another specific object is to provide a detonator and primer-carriermovable, upon impact of the projectile, toward the firing pin, andembodying novel means for locking the same at the limit of suchmovement.

With these objects in view, the invention resides, generally stated, ina base-detonating fuse embodying a normally restrained and unarmedfiring pin, and means for arming the firing pin, comprisingcentrifugallydno vable spring members co-operating with locking meansfor holding the firing- .pin in restrained position, with itsdrivingspring compressed.

- The invention resides, further, in a detonator and primer carrier,comprising a plunger movable, upon impact ofthe projectile, toward thefiring-pin, and provided with a rim, which is deformable or crushable,upon impact with a stationary member limiting the travel of the plunger,into a locking recess, whereby the plungeris locked against recoil.

The invention resides, finally, in certain refinements. of structuregoing to make up the ultimate perfection of the fuse, as an entirety.

The invention is graphically shown in the accompanying drawings, whichdisclose an exemplary embodiment capable of carrying out the underlyingprinciplesof the invention; Like reference characters correspondingparts throughout the several views. Briefly described:

Figure 1 .is a centrahlongitudinal section through the fuse of myinvention, showing the normal position of the parts thereof;

F gure 2 is a similar view, showing the position of theparts afterimpact of the projectile carrying the fuse;

Figure 3 i'sa developmentof the arming casing;

Figure casing;

Figure 5 is a view in side elevationofthe firing-pin support.

Referring, now, in detail, tothe drawings:

1 designates the fuse-stock preferably provided with a circumferentialbase-flange 2, and exteriorly threaded portion 3 adjacent said flange,an intcriorly threaded portion 4 at the nose end,and a centrallyapertured diaphragm '5 ate point between the longitudinal center ofthestock and the base thereof. The space between the diaphragm 5 and thethreaed plug 9 closing the base of the stock constitutes a safetychamber 6. The side 7 of said diaphragm facing the safety chamber ispreferably substantially conoidal, as shown. Preferably, the wall of thesafetychamber 6 is weakenedby a circumferential groove 8,affordingfrangibility. 1

Rectilinearly movable in the central aperture of the diaphragm 5 is adetonator carrier 11, which, as shown, is an elongated body of crosssectional area substantiallythe same as that of the central openingofthe diaphragm 5, and having, at its forward end, a head 12 and, at itsrear, a pocket or cavity for the reception of the detonator 13. The thinend of the carrier is crimped over the detonator, forming a marginalfiange l i, which holds the detonatorin position. i I

The carrier head 12 islrecessed for thereception of the primer 15, andthe .carrieris longitudinally bored, a s shown at 16, afford. ing aflash passage from the-primer to-Qthe detonator. 1

Preferably, a sleeve or bushing 23 encirclesthe carrier 11, and theforward end of A is a view in section of said the sleeve is crimped overto provide'an andesignate nular flange 24 seated against the inner surface ofan inward-projecting, circumferential flange 25 laterally carriedby a tubular member 26, provided, at its opposite end, with a marginal,outward-projecting flange 27 peripherally threaded, as shown, so thatthe member 26 may be threaded into the threaded portion 4 of thestock 1,as clearly shown in Fig. 1. The member 26 functions as a support for thedetonatorcarrier 11, and, also, as a guard to prevent the flame of theprimer reaching the booster-charge 28, should the primer be accidentallyfired while the parts are in the normal position 1 shown in Fig. 1.

As shown in Fig. 1, the head 12 of themally retained in this position bysuitable mechanical means, in this instance by centrifugally-operablelocking bolts 17, any suitable number of which may be employed,equidistantly spaced, and housed in radial openings 18 in the diaphragm5. The inner ends'of the locking bolts are normally projected intoperipheral notches 19 in the carrier 11 by coiled springs 20 bearingagainst the outer ends of the bolts and against disks 21'secured in theenlarged outer ends 22 ofthe openings 18. The function and operation ofthese centrifugal locking bolts 17 s are well understood inthe art, andwill not be dwelt upon herein. 1

Thefcarrier-head 12 is provided, at its free end, with a deformablelocking-rim 30, which, when the carrier 11 is driven for ward andstrikes against a head 35, is crushed or deformed or upset into acounterbore or recess 32 in the forward end of the tubularcarrier-support 26, thus locking the carrier against recoil.

Seated inth'e forward end of the stock 1 is a tubular bushing or housing33 provided with an exteriorly threaded portion 34,'by whichthe bushingmay be. screwed into the stock. The housing 33 is provided, atone end,with an outward-projecting, marginal flange, 36, which, when the bushingis screwed home? in the stock 1, bears against the outer end thereof, sshown 1 .181 1, The bushing is also provided with an internally-threadedportion 37, at the flange end thereof, for engagement with the threadedportion ora closure-plug 38.

.The firing pincomprises the shank 39 terminating, at one end, in thetapering pointed portion 40, and an integral collar diametric peg 42projecting,

41 carrying a at both ends, beyond the periphery of the firing-pinshank, for the purpose presently. appearing. Thefiring-pin, collar; andpeg may be made integral, i. e., the collar be provided with integrallugs or projections, corresponding to theprojecting ends of the peg 42.

The firing pin is reciprocable in a support 43, which, as shown, is atubular member provided, at one end, with an outwardprojecting marginalflange 35, which, in the assembled position of the parts, is seatedagainst the flange 27 of the carrier support 26, and is disposed betweensuch flange 27 and the inner end of the bushing 33.

The firing-pin support 43 is provided with the longitudinally-extending,diametrically oppositely disposed, slots.44, 44, of differing lengths.Intermediate the ends thereof one of the slots is provided with anoffset portion or branch 45 one of the side walls 46 thereof "beinginclined or oblique to the slot 44, as clearly shown in Fig. 4, for thepurpose presently appearing. The other slot has a lateral offset orbranch 45.

Encircling the shank 39 of the firing-pin is a coiled spring 47, one endthereof bearing against the firing-pin collar 41and the other'endagainst a cup 49, in which the forward portion of the firing pin support43 is seated. Between said cup and the screw closure plug 38 is a leadwasher 49, to take up the recoil of thefiring-pin. 7

The firing-pin driving springf47 is normally under compression, and isprevented from propelling the firing-pin rearward by having theprojecting ends of the peg 42 seated in the offset portions 45 of theslots 44, and retained in this position by the following m ans:

A locking-sleeve 5O encircles and is longitudinally movable on thefiring-pin support 43. Disposed interiorly of the sleeve 50 is alocking-dog 52provided with a stem 51 extending transversely through thewall of the sleeve, whereby the locking dog is secured to and is thuscarried by the sleeve 50,

The locking-clog is seated and reciprocates in that slot 44 which hasthe greater length. Normally, the locking dog 52 is disposed in 'thepathof movement of the peg 42 from the offset portion 45 of the slot 44 andblocks passage of the peg from such offset portion to said slot, asshown in Fig. '1.

The locking sleeve 50 may be provided with a sloping exterior surface53, terminat- I ing, at one end, at a shoulder 58 encircling the sleeve.f 1

Centrifugally-operable means are provided for normally maintaining thelocking sleeve 50 with the locking-dog 52 in locking position, as shownin Fig. 1, and I have shown in the drawings my preferred means, which Iwill now describe:

.Disposed between the inner-end of the plug 38 and the tubular bushing33 is a metallic arming casing, which, as shown, is a. ring or band 56carrying a series of equidistantly spaced, spring fingers 57,-bent orinclined so as to converge at their free ends, as shown in the drawings.The inclined spring fingers bear against the inclined sur face 53 of theloking sleeve 50, and the free ends thereof bear against the shoulder58, thus preventing longitudinal movement of the sleeve 50 in adirection to release the firing pin.

Preferably, at least one of the spring fingers 57 is crimped, on the arcof a circle, as shown at 59, at a point adjacent the ring 56, formingwhat may be termed a hump, which normally enters the space bet-ween theadj acent ends of the locking-sleeve 50 and the plug 38.

Advantageously, the spring fingers 57 and the ring 56 are formedintegral, as by being stamped out of a blank of spring metal, and bentup to form.

\Vhile the operation .of the fuse is, probably, apparent from theforegoing descrip tion of the construction and the relation of theparts, it may he briefly explained as follows:

The normal position of the parts is as shown in Fig. 1, wherein thedetonator-carrier 11 is locked against movement by the locking bolts 17,and wherein the firing-pin driving spring 47 is compressed and thefiring-pin turned so that the projecting ends of the peg 42 are seatedin the offset portions or branches 1-5 of the slots 44, 44:, andretained therein by the locking-dog 52 carried by the locking-sleeve 50.During flight, when the centrifugal force acting on the locking-bolts 17overcomes the inertia thereof, i. e.. when positive linear accelerationceases, they move radially outward, thus releasing the detonator-carrier11.

Also, when centrifugal force acting on the spring fingers 57 becomessufficiently great, they flex outward, releasing the lockingsleeve 50and arming the firing-pin.

Upon impact, the projectile and fuse are retarded throughout theduration of the resistance encountered. 'The tendency of all parts onthe interior of the fuse is to move forward through the force due toinertia of these parts. The carrier 11, therefore, drives forwardagainst the head 35, crushing the rim 30 into the counterbore 31,thereby locking the carrier against recoil. The-locking sleeve 50, beingno longer prevented from moving forward. also slides forward against theinner end of the plug 38, the lockingdog 52 moving with the sleeve so asto uncover the offset portion in which the corresponding projecting endof the peg 42 is seated. As the sleeve drives forward, it brushesby theoffset portion 59, flexing the same outward. As will be understood, the

hump 59 functions as a SiLfGtV-Ppnnns t mvent premature movement of thesleeve 50 after the spring fingers, under centrifugal force, release thesleeve. 7

.So long as theresistance is such as to cause the inertia of the firingpin and spring to produce a force greater than and counter ually, thefiring-pin spring would also extend 'raduall and conse uentl the firin ay a q ya a: pin, moving thus slowly under the lnfluence of the slowlyexpanding spring, would not,

have sufficient force [to fire the primer. To obviate such anoccurrence, means are provided for retarding the extension of the springuntil sufficient force is accumulated therein to fire the primer whenthe spring extends. This retardation of action of the spring isaccomplished by cuttingthe inclined wall 46 of the branches 45., inwhich the projecting ends of the peg 42-i'ests, at such an angle-to theslots 44 that it will require a force sufficiently great to fire the primer, to overcome friction between the peg ends and said oflset portionsand drive the projecting ends of the peg into the longitudinal slots 44,44. It will thus be seen that a gradual cessation of resistance topenetration will not cause the spring 47 to extend gradually, but withsufficient force, in all cases, to fire the primer. The projecting endsof the peg 42 rotate out of the branches 4:5 and then, with alongitudinal movement, the firing pin is propelled, under the action ofits driving spring, against the primer.

The action of the fuse gives an automatic selective delay in firing,through mechanical means, the delay, in all cases, being proportional tothe resistance encountered.

Having thus fully described my invention, what I claim as new anddesireto secure by Letters Patent is 1. In a fuse, the combination, with anormally-restrained firing pin carrying a radial projection andreleasable by an axial turning movement, of a casing in which saidfiring pin reciprocates and-having a longitudinally-extending slot in"which the firing-pin projection moves when the firing-pinreciproc'ates, said slot being provided with an offset portion in whichsaid projection normal- 1y rests, a locking-dog reciprocable in saidslot and normallyfholding said projection in said offset portion of theslot, and means for normally holding said dog in such'operalilo lit)

tive locking position, including centrifugal-v ly-movable spring lockingmembers.

2. In a fuse, the combination, with a normally-restrained firing pincarrying a radial projection and releasable by an axial turningmovement, of a casing in which said firing pin reciprocates and having alongitudinally-extending slot in which the firingpin projection moveswhen the firing-pin reciprocates, said slot being provided with anoffsetportion in which said projection normally rests, a locking-dogreciprooable in said slot and normally holding said projection in saidoffset portion of the slot, a locking-sleeve encircling said casing andcarrying said locking-dog, and -centrifugallymovable spring membersnormally preventing movement of said lockin -sleeve.

3. In a fuse, the combination, with anorznallyq'estrained firing pincarrying a radial projectionand releasable by an axial turning movement,of'a casing in which said firing pin reciprocates and having alongitudinally-extending slot in which the firing-pin projection'moveswhen the firing-pin reciprocates, said slot being provided with anoff-set portion in which said projectionnormally rests, a locking-dogreciprocable in said slot and normally holding said projection in saidoffset portion of the slot, a locking-sleeve encircling said casing andcarrying said locking-dog, and a member carrying centrifugally-movablespring fingers normally resting upon said locking-sleeve and preventingmovement thereof.

4-. In a fuse, the combination, with a normally-rcstrained firing pincarrying a radial projection and releasable by an axial turningmovement, of a casing in which said firing pin reciprocates and having alongitudinally-extending slot in which the firin -pin projection'moveswhen the firing'pin reciproca'tes, saidslot being provided with an,offset portion in which said projection nor mally rests, a locking-dogreciprocable in said slot and normally holdingsaid projection in saidoffset portion of the slot, a locking-sleeve encircling said casing andcarrying said locking-dog, and centrifugally-movable leaf-springsnormally bearing against said locking-sleeve and preventing movementthereof. v

In a fuse, the combination, with a normally-restrained firing pincarrying a radial projection and releasable by an axial turningmovement, ofa casin in which said firing pin reciprocates, and having alongitudinally-exten'ding slot in which the firing pin projection moveswhen the firing pin-recipro cates, said slot being provided with anoffset portion in which said projection normally rests, a locking-dogreciprocable in said slot and normally holding said projection in saidoffset portion of the slot, a locking-sleeve encircling said casing andcarry ing said locking-dog, and an annular member carryingajcircularly-arranged series of spring fingersnormally bearing upon saidlocking-sleeve and preventing movement thereof.

, 6. In a fuse, the combination, with a normany-restrained firing pm,carrying a radial projection and releasable by an axial turningmovement, of a casing in which said firing pin recipr0cates,and having alongiinclined exterior surface, and centrifugallymovable leaf-springsnormally bearing against said inclined surface and preventing movementof said locking-sleeve.

7. In a fuse,;the combination, with a normally-restrained firing pincarrying a radial projection and releasable by an axial turning movement,of a casing in whichsaid firing pin reciprocates, and having alongitudinally-extending slot in'which the firing-pin projection moveswhen the firing pin recipro cates, said slot being provided with anoffset portion in which said projection normally rests, a locking-dogreciprocable in said slot and normally holding said projection in saidoffset portion of the slot, a lockingsleeve encircling-said casing andcarrying said locking-dog and provided withan annular circumferential'shoulder, and 'centrifu gally-movable leaf-springs normally bearingagainst said shoulder and preventing movement of said locking-sleeve. 1f

8. In a fuse, the combination, with a normally-restrained firing pincarryinga radial projection and releasable by an axial turning movement,of a casing in .whichsaid firing pin reciprocates, and having alongitudinal ly-extending slot in which the firing pin projection moveswhen the firing pin reciprocates, said slot beingprovided with an offsetportion in which said projection normally rests, a locking-dog,reciprocable in said'slot and normally holding said projection in saidoffset portion of the slot,

a locking-sleeve encircling said casing and carrying said locking-dogand provided with an annular circumferential shoulder, and

centrifugally-movable leaf-springs: normally bearing against saidshoulder and preventng" movement 'of said locking-sleeve, one

of said leaf-springs being crimped to provide an offset portion normallybearing against .one end of said locking-sleeve.

9. In a 'fuse, the combination, with the firing pin, of the drivingspring therefor, means for normally maintaining said firing pin inunarmed position, with its spring compressed, including a movablelocking member and centrifugally-movable locking springs normallyco-operating with said locking member, and means carried by one of saidsprings for yieldingly holding said locking member against movementafter release thereof by said springs under centrifugal force.

10. In a fuse, the combination, with the firing pin, of the drivingspring therefor, means for normally maintaining said firing pin inunarmed position, with its spring compressed, including a movablelocking member and centrifugally-movable locking springs normallyco-operating with said locking member, and a flexible projection carriedby one of said springs and normally bearing against said locking memberfor yieldingly holding it against movement after release thereof by saidsprings under centrifugal force.

11. A fuse provided with a reotilinearlymovable primer-carrying plungercarrying means deformable for locking the same near the limit of itstravel.

12. A fuse provided with a rectilinearly-.

movable primer-carrying plunger carrying a member at one end't-hereofdeformable for locking the same near the limit of its travel.

13, A fuse provided with a rectilinearlymovable primer-carrying plungercarrying a deformable rim at one end thereof for locli- 15. In fuse, afiring-pin, a primer-carry-' ing plunger movable toward said firing pin,and means carried by said plunger deformablefor looking the plungerafter movement toward said firing pin.-

JOHN H. WOODBERRY.

